The major objective of the Transgenic / Gene-Disruption Mouse Core is to provide a centralized service oriented facility that will insure the capacity of each participating project lab to produce transgenic and gene-disrupted mice. Moreover, this will result in an economy of effort as well as expense by avoiding duplication of a highly technical skill requiring specialized equipment and animal facilities. The Transgenic / Gene-Disruption Core is a major avenue for collaborations. The ability to perform gain of function and loss of function experiments in vivo will enhance our understanding of the molecular mechanisms guiding airway inflammation and the pathogenesis of asthma. Moreover, the capacity to follow the tissue and cell type expression of a Promoter/Enhancer combination throughout normal embryonic and adult development is crucial to furthering our understanding of airway differentiation and regulation of inflammation.